<p>
  <select [(ngModel)]="placement" class="form-control">
    <option *ngFor="let placement of placements"
      [value]="placement">
      {{ placement }}
    </option>
  </select>
</p>
<button type="button" class="btn btn-default btn-secondary"
  [popover]="'Vivamus sagittis lacus vel augue laoreet rutrum faucibus.'"
  [popoverTitle]="'Popover on ' + placement"
  [placement]="placement">
  {{ 'Popover on ' + placement }}
</button>
